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esp32_Adafruit_BusIO
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Merge pull request #93 from eringerli/cs-transaction-management 

better transaction management
This commit is contained in:
Limor "Ladyada" Fried 2022-05-02 18:29:00 -04:00 committed by GitHub
parent 204c1de9ab f82f699c64
commit b949d28bde
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 40 additions and 48 deletions
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86
Adafruit_SPIDevice.cpp
View File

@ -282,6 +282,36 @@ void Adafruit_SPIDevice::endTransaction(void) {
}
}
/*!
* @brief Assert/Deassert the CS pin if it is defined
* @param value The state the CS is set to
*/
void Adafruit_SPIDevice::setChipSelect(int value) {
if (_cs != -1) {
digitalWrite(_cs, value);
}
}
/*!
* @brief Write a buffer or two to the SPI device, with transaction
* management.
* @brief Manually begin a transaction (calls beginTransaction if hardware
* SPI) with asserting the CS pin
*/
void Adafruit_SPIDevice::beginTransactionWithAssertingCS() {
beginTransaction();
setChipSelect(LOW);
}
/*!
* @brief Manually end a transaction (calls endTransaction if hardware SPI)
* with deasserting the CS pin
*/
void Adafruit_SPIDevice::endTransactionWithDeassertingCS() {
setChipSelect(HIGH);
endTransaction();
}
/*!
* @brief Write a buffer or two to the SPI device, with transaction
* management.
@ -296,11 +326,8 @@ void Adafruit_SPIDevice::endTransaction(void) {
bool Adafruit_SPIDevice::write(const uint8_t *buffer, size_t len,
const uint8_t *prefix_buffer,
size_t prefix_len) {
if (_spi) {
_spi->beginTransaction(*_spiSetting);
}
beginTransactionWithAssertingCS();
setChipSelect(LOW);
// do the writing
#if defined(ARDUINO_ARCH_ESP32)
if (_spi) {
@ -320,11 +347,7 @@ bool Adafruit_SPIDevice::write(const uint8_t *buffer, size_t len,
transfer(buffer[i]);
}
}
setChipSelect(HIGH);
if (_spi) {
_spi->endTransaction();
}
endTransactionWithDeassertingCS();
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.print(F("\tSPIDevice Wrote: "));
@ -361,17 +384,10 @@ bool Adafruit_SPIDevice::write(const uint8_t *buffer, size_t len,
*/
bool Adafruit_SPIDevice::read(uint8_t *buffer, size_t len, uint8_t sendvalue) {
memset(buffer, sendvalue, len); // clear out existing buffer
if (_spi) {
_spi->beginTransaction(*_spiSetting);
}
setChipSelect(LOW);
beginTransactionWithAssertingCS();
transfer(buffer, len);
setChipSelect(HIGH);
if (_spi) {
_spi->endTransaction();
}
endTransactionWithDeassertingCS();
#ifdef DEBUG_SERIAL
DEBUG_SERIAL.print(F("\tSPIDevice Read: "));
@ -405,11 +421,7 @@ bool Adafruit_SPIDevice::read(uint8_t *buffer, size_t len, uint8_t sendvalue) {
bool Adafruit_SPIDevice::write_then_read(const uint8_t *write_buffer,
size_t write_len, uint8_t *read_buffer,
size_t read_len, uint8_t sendvalue) {
if (_spi) {
_spi->beginTransaction(*_spiSetting);
}
setChipSelect(LOW);
beginTransactionWithAssertingCS();
// do the writing
#if defined(ARDUINO_ARCH_ESP32)
if (_spi) {
@ -455,11 +467,7 @@ bool Adafruit_SPIDevice::write_then_read(const uint8_t *write_buffer,
DEBUG_SERIAL.println();
#endif
setChipSelect(HIGH);
if (_spi) {
_spi->endTransaction();
}
endTransactionWithDeassertingCS();
return true;
}
@ -475,29 +483,11 @@ bool Adafruit_SPIDevice::write_then_read(const uint8_t *write_buffer,
* writes
*/
bool Adafruit_SPIDevice::write_and_read(uint8_t *buffer, size_t len) {
if (_spi) {
_spi->beginTransaction(*_spiSetting);
}
setChipSelect(LOW);
beginTransactionWithAssertingCS();
transfer(buffer, len);
setChipSelect(HIGH);
if (_spi) {
_spi->endTransaction();
}
endTransactionWithDeassertingCS();
return true;
}
/*!
* @brief Assert/Deassert the CS pin if it is defined
* @param value The state the CS is set to
*/
void Adafruit_SPIDevice::setChipSelect(int value) {
if (_cs == -1)
return;
digitalWrite(_cs, value);
}
#endif // SPI exists

2
Adafruit_SPIDevice.h
View File

@ -88,6 +88,8 @@ public:
void transfer(uint8_t *buffer, size_t len);
void beginTransaction(void);
void endTransaction(void);
void beginTransactionWithAssertingCS();
void endTransactionWithDeassertingCS();
private:
SPIClass *_spi;